Switch



J 30, 1949. J. RIGGS 2,188,725

SWITCH Filed Jan. 10, 1959 2 Sheets-Sheet 1 In ventor A itorneys;

Patented Jan. 30, i940 RAE For.

swrrcn Joseph ltiggs, Pound, Va., assignor of fifty per cent to Thurman M. Perry, Jenkins, Ky.

Application January 10, 1939, Serial No. 250,201

1 Claim.

This invention appertains to new and useful improvements in safety switches for shot firing cables.

The principal object of the present invention is to provide a safety switch for shot firing cables which will serve in a fool-proof manner to prevent premature discharging of the shot.

Another important object of the invention is to provide a safety switch which will be of simple construction and easy and convenient to operate.

These and other objects and advantages of the invention will become apparent to the reader of the following specification.

In the drawings:

Figure 1 represents a top plan view of the switch, shown in conjunction with a blasting battery and shot cable.

Figure 2 is a side elevational view.

Figure 3 is an edge elevationalview of the switch.

Figure 4 is a top plan view of the switch with one body section removed.

Figure 5 is a top plan View of the switch with one bottom section removed and showing the switch in open oposition.

Figure 6 is a section on the line 56 of Figure 1.

Figure '7 is a fragmentary perspective View showing one of the switch springs.

Figure 8 is a fragmentary side elevational view showing one of the cable attaching prongs modifled to provide a binding screw.

Referring to the drawings wherein like numerals designate like parts, it can be seen that the switch ismade up of the lower section 5 and the upper section 6. These sections make up the body of the switch and are preferably of insulation. The upper section is recessed as at I and has a pair of longitudinally extending grooves 'l8 for receiving the intermediate portions of the elongated stiff members 9 and II], respectively. One end of each of the members 9-45] is formed with an eye ll through which the conductors l2 and I3 are disposed. These conductors are further wound as at I4 about the adjacent portions of the elongated members 8 and I!) to properly secure the same in place. The cable I5 is twisted as shown in Figure 1 and leads to the shot 16.

The intermediate portion of each of the elongated members 9-l0 has a substantially V- shaped contact spring I! secured thereto by one of its ends, by solder or Welding l8. The free ends of thesprings l'l--l1 bear against the boss I9 which projects into the pocket I, when the contactor 20 is disengaged therefrom. This contactor 20 has a pair of diverged leg members 2 I-2l which engage the free end portions of the springs I'l-ll flatly as shown in Figure 4 when the contactor 20 is allowed to become positioned against the boss IS in response to the tension of the spring 22, this spring 22 being convoluted i the body, is provided with the finger engag'eable head 25.

The remaining ends of the elongated rigid conductor-members 9-!0 diverge as at 26 and then extend as at 21 so as to avoid ample clearance for manipulation of the "stem 23 by the head 25.

The portions 21-41 serve as contact prongs for engagement into the contact socket 28 of the blasting battery 29.

It can now be seen, that normally the spring 22 maintains the contactor bridging the springs Illl and thus the battery is grounded and no current can reach the shot It.

However, when it is desired to discharge the shot Hi, all that is required is to force the head of the stem 23 inwardly and this disengag'es the contactor 2'43 from the spring l'l-il, thus permitting the current from the battery to pass through the cable l5 to set ofi the charge 16.

A modified form of elongated conductor member 9 or ill is shown in Figure 8 wherein the cable end is flattened as at 9;; and has a binding screw Ha threadedly disposed therein.

While the foregoing specification sets forth the invention in specific terms, it is to be understood that numerous changes in the shape, size and materials may be resorted to without departing from the spirit and scope of the invention. as claimed hereinafter.

Havingdescribed the invention, what is claimed as new is:

A safety switch of the character described comprising a body having a pair of elongated substantially rigid conductor members extending therethrough, said body being provided with an internal pocket, a pair of substantially V-shaped spring contact fingers, each of these said spring contact fingers having one leg portion secured to a corresponding rigid conductor, the remaining leg portions of the fingers convergingtoward each other, a push rod, a spreader of insulation between the rigid conductors through which the push rod is slidable, said spreader provided with a boss there'- on against opposite side portions of which the free ends of the spring fingers can engage and normallybe separated, a tapered contactor carried by the push rod, a second spreader between the rigid conductors and a compression spring interposed between the second-mentioned spreader and the contactor for normally urging the rod and contactor to a position with the contactor normally bridging the free end portions of the spring contact members.

JOSEPH RIGGS. 

